Targeting landmarks of orthopaedic devices

• US 9,526,441 B2
• Filed: 05/03/2012
• Issued: 12/27/2016
• Est. Priority Date: 05/06/2011
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Wilhelm, Hoa La, Rains, James K., Hampton, Daniel, Petteys, Timothy J., Gerlach, Darin S.
• Primary Examiner(s): Hammond, Ellen C
• Assistant Examiner(s): BRAY, STUART SAMUEL
• Application Number:
  US14/114,940
• Publication Number:
  US 20140081121A1
• Time in Patent Office: 1,699 Days
• Field of Search: 606/97, 606/309, 600/424
• US Class Current: 1/1
• CPC Class Codes: A61B 17/1703 using imaging means, e.g. by X-rays
• CPC Class Codes: A61B 17/1707 using electromagnetic effects, e.g. with magnet and external sensors
• CPC Class Codes: A61B 17/1725 for applying transverse screws or pins through intramedullary nails or pins
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/7241 the nail having separate elements through which screws pass
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/8057 the interlocking form comprising a thread
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 2017/00199 with a console, e.g. a control panel with a display
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/0036 including treatment, e.g., using an implantable medical device, ablating, ventilating
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

A method for targeting a landmark of an orthopaedic implant comprises implanting the orthopaedic implant in a body. The orthopaedic implant having at least one landmark defining two or more locations for targeting and a first magnetic sensor located at a known distance from at least one of the two or more locations. The method includes comprises identifying one of the locations using a landmark identifier, the landmark identifier having at least one of a second magnetic sensor and a magnetic field generator, installing a transfixion element in the at least one landmark, and identifying a second location using the landmark identifier.

Claims

1. An apparatus comprising:

one or more processing devices and one or more storage devices storing instructions that are operable, when executed by the one or more processing devices, to cause the one or more processing devices to perform operations comprising;

receiving signals from a magnetic sensor located at a known position relative to an orthopaedic implant, the orthopaedic implant defining a hole that admits a transfixion element, the hole being defined to admit a transfixion element at two or more targeting locations in the hole;

selecting a first targeting location of the two or more targeting locations, wherein selecting the first targeting location comprises;

accessing information indicating an amount of bone compression; and

selecting, as the first targeting location, a location at which insertion of a transfixion element will cause the amount of bone compression;

determining, based on the signals, a position of a landmark identifier relative to the first targeting location; and

indicating the position of the landmark identifier relative to the first targeting location.

2. The apparatus of claim 1, wherein the hole is defined to include an elongated region and a circular region.

3. The apparatus of claim 2, wherein the circular region has a diameter, the elongated region comprises a length and a width, and the length is greater than the diameter.

4. The apparatus of claim 3, wherein the two or more targeting locations comprise at least one of a center point of the elongated region and a center point of the circular region.

5. The apparatus of claim 1, wherein the operations further comprise:

receiving second signals from the magnetic sensor;

determining, based on the second signals, a position of the landmark identifier relative to a second targeting location of the two or more targeting locations; and

indicating the position of the landmark identifier relative to the second targeting location.

6. The apparatus of claim 5, wherein:

indicating the position of the landmark identifier relative to the first targeting location comprises indicating a location for installing a non-locking fastener; and

indicating the position of the landmark identifier relative to the second targeting location comprises indicating a location for installing a locking fastener.

7. The apparatus of claim 1, wherein the two or more targeting locations comprise a targeting location in a threaded region of the hole and a targeting location in a non-threaded region of the hole.

8. The apparatus of claim 1, wherein determining, based on the signals, the position of the landmark identifier relative to the first targeting location comprises:

accessing information about characteristics of the orthopaedic implant; and

accessing information about the position of the magnetic sensor relative to the orthopaedic implant; and

wherein determining the position of the landmark identifier relative to the first targeting location is further based on the information about the characteristics of the orthopaedic implant and the position of the magnetic sensor relative to the orthopaedic implant.

9. The apparatus of claim 1, wherein the operations further comprise:

receiving second signals from the magnetic sensor;

determining, based on the second signals, a position of the landmark identifier relative to a second targeting location in a second hole; and

indicating the position of the landmark identifier relative to the second targeting location.

10. The apparatus of claim 1, wherein the first targeting location is offset from a central location of the hole.

11. The apparatus of claim 1, wherein selecting the first targeting location comprises:

receiving user input; and

selecting the first targeting location based on the user input.

12. A method for targeting a landmark of an orthopaedic implant, the method comprising:

implanting the orthopaedic implant in a body, the orthopaedic implant having at least one hole defining two or more locations for targeting and a first magnetic sensor located at a known distance from at least one of the two or more locations;

identifying a first location of the two or more locations using a landmark identifier, the landmark identifier having at least one of a second magnetic sensor and a magnetic field generator;

installing a transfixion element in the at least one hole at the identified first location; and

after the transfixion element has been installed and while the transfixion element is in the at least one hole, identifying a second location of the two or more locations using the landmark identifier.

13. The method of claim 12, wherein the hole comprises an elongated portion and a circular portion.

14. The method of claim 13, wherein the elongated portion comprises a length and a width, and the circular portion has a diameter, and the length is greater than the diameter.

15. The method of claim 13, wherein the two or more locations comprise at least one of a center point of the elongated portion and a center point of the circular portion.

16. The method of claim 12, further comprising installing a second transfixion element in the at least one hole at the identified second location.

17. The method of claim 16, wherein the second transfixion element comprises a locking screw.

18. The method of claim 12, wherein the transfixion element comprises a non-locking screw.

19. The method of claim 12, wherein the implant is at least one of a nail and a plate.

20. The method of claim 12, wherein identifying the first location of the two or more locations using a landmark identifier comprises:

identifying, as the first location, a target location of the two or more locations that corresponds to a predetermined amount of compression of bone fragments of a fractured bone of the body.

21. A method for facilitating a bone compression procedure, the method comprising:

determining a position of an instrument relative to a target location using an electromagnetic targeting system, the target location being located in a hole defined in an orthopaedic implant, the hole being defined to admit a transfixion element at two or more locations in the hole;

displaying, on a display device, representations of the orthopaedic implant, the hole, and the target location;

indicating, on the display device, the position of the instrument relative to the target location; and

indicating, on the display device, an amount of compression to be applied between bone fragments of a fractured bone by insertion of a transfixion element at the target location.

22. The method of claim 21, further comprising:

receiving user input; and

in response to receiving the user input, changing the target location from a first location of the two or more locations to a second location of the two or more locations.

23. The method of claim 22, wherein:

receiving user input comprises receiving user input that indicates a specified amount of bone compression; and

changing the target location from a first location of the two or more locations to a second location of the two or more locations comprises;

determining, as the second location, a location at which insertion of a transfixion element will cause the specified amount of bone compression; and

indicating, on the display device, the position of the instrument relative to the second location.

24. A system comprising:

an electromagnetic field generator;

an orthopaedic implant defining at least one hole that defines two or more targeting locations for receiving a transfixion element, the orthopaedic implant having a magnetic sensor located at a known location relative to at least one of the two or more locations;

a landmark identifier; and

a control unit configured to;

access information indicating an amount of bone compression;

select, from among the two or more locations, a target location at which insertion of a transfixion element will cause the amount of bone compression;

receive signals from the magnetic sensor;

determine a position of the landmark identifier relative to the target location based on the received signals; and

indicate the position of the landmark identifier relative to the target location.